• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11C
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• pp.1040-1048
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• 2009

This paper proposes an auto flesh tone balance algorithm for the picture that is taken for people. General white balance algorithms bring neutral region into focus. But, other objects can be basis if its spectral reflectance is known. In this paper the basis for white balance is human face. For experiment, first, transfer characteristic of image sensor is analyzed and camera output RGB on average face chromaticity under standard illumination is calculated. Second, Output rate for the image is adjusted to make RGB rate for the face photo area taken under unknown illumination RGB rate that is already calculated. Input tri-stimulus XYZ can be calculated from camera output RGB by camera transfer matrix. And input tri-stimulus XYZ is transformed to standard color space (sRGB) using sRGB transfer matrix. For display, RGB data is encoded as eight-bit data after gamma correction. Algorithm is applied to average face color that is light skin color of Macbeth color chart and average color of various face colors that are actually measured.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2373-2375
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• 2002

전자 제어식 미끄럼 방지 제동 장치(ABS, Anti-lock Brake System)를 장착한 차량의 실차 제동 시험은 시험용 차량을 비롯하여, 많은 분석장비를 필요로 한다. 이러한 고가의 장비는 구하기가 어려울 뿐만 아니라 사용방법을 학습하는 데에도 상당한 기간을 필요로 하므로, 개발중인 ABS에 대하여 적용해 보기에는 그 사용에 제약을 받는다. 본 논문에서는 개발중인 미끄럼방지 제동 알고리즘과 전자제어장치(ECU, Electronic Control Unit)를 대형 버스에 장착하여, 저 점착 노면에서 주행 시험을 시행하였고, 그 주행 기록의 분석을 위하여 DAS(Data Acquisition System)를 구현하였다. 개발 ABS 알고리즘 및 ECU의 기능과 성능 검증이 목적인 DAS는 부가적인 센서 및 고가의 장비를 사용하지 않고 제어보드와 휴대용 노트북 컴퓨터를 이용하였다. 고정밀도의 자료를 획득할 수는 없었지만, 개발 DAS를 이용한 차량 실차 제동 시험은 경제적이면서도 효과적인 ECU 및 알고리즘의 성능 분석을 이룰 수 있었다. 특히 개발 DAS는 제어 및 Data Acquisition을 동일한 보드를 사용하여 구현함으로써, ABS 장착 실차 주행 시험 결과를 제어알고리즘에 즉각적으로 반영시킨 수 있었다. 이러한 One Board System 및 On-Vehicle Programming을 이용한 방법은 개발 알고리즘의 빠른 Debugging 및 파라미터 조정(Tuning)을 가능하게 하였으므로, 실차 제동 시험을 위한 한정된 기간 내에 개발 ABS ECU 및 제어 알고리즘의 성능을 효과적으로 검증할 수 있었다.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.1
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• pp.101-106
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• 2016

In this paper, we analysed correlation between scores and posture of amateur archer with inertial sensor based motion analysis system. Four 13 to 15 yeared subjects are participated and accelerations of upper and forearms are measured during shooting. Each subject carried out six end. And they shoot arrows six times per each end from 30 meters away. We extracted and analyzed acceleration values during full throw. In the case of left arm, we could not found any meaningful correlation with score. Meanwhile, acceleration values of right arm have certain correlation with score. It seems that aiming skill of right arm is very important while left arm settles stably.

• Journal of Industrial Convergence
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• v.18 no.1
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• pp.79-85
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• 2020

Recently, the RPAS(Remote Piloted Aircraft System), by remote control and autonomous navigation, has been increasing in interest and utilization in various industries and public organizations along with delivery drones, fire drones, ambulances, agricultural drones, and others. The problems of the stability of unmanned drones, which can be self-controlled, are also the biggest challenge to be solved along the development of the drone industry. drones should be able to fly in the specified path the autonomous flight control system sets, and perform automatically an accurate landing at the destination. This study proposes a technique to check arrival by landing point images and control landing at the correct point, compensating for errors in location data of the drone sensors and GPS. Receiving from the Google Map API and learning from the destination video, taking images of the landing point with a drone equipped with a NAVIO2 and Raspberry Pi, camera, sending them to the server, adjusting the location of the drone in line with threshold, Drones can automatically land at the landing point.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.211-216
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• 2012

Control Theory for continuous-time system has been well developed. Due to the development of computer technology, digital control scheme are employed in many areas. When delays are in control systems, it is hard to control the system efficiently. Delays by controller-to-actuator and sensor-to-controller deteriorate control performance and could possibly destabilize the overall system. In this paper, a new approximated discretization method and digital design for control systems with multiple state, input and output delays and a generalized bilinear transformation method with a tunable parameter are also provided, which can re-transform the integer time-delayed discrete-time model to its continuous-time model. Illustrative example is given to demonstrate the effectiveness of the developed method.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.3
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• pp.22-28
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• 2007

The STIR(Signal Tracking & Illumination Radar) in KDX(Korean Destroyer Experimental) combat system acquires target from designating 3-D target information of surveillance radar (MW-08), and The performance of radar is decided by target acquisition time and accuracy of tracking loop because the STIR tracks automatically in accordance with tracking algorithm. In the view of ship, elements related with target acquisition time of the STIR can be various. In this paper the target acquisition time of the STIR is reduced by identifying the elements and suggesting the performance improvement method. The way of performance improvement is suggested through analysing main affecting factors. First, tracking algorism is required for analysis. Second, fitness of parameters that control elements related with acquisition distance is analyzed. And the third, accuracy of ship based sensors is analyzed. In conclusion, acquisition time against ship target can be advanced to 3 seconds from 10 seconds.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.12
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• pp.769-775
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• 2016

Characteristics of a wireless sensor powered by the IDE (interdigitated electrode) embedded piezoelectric cantilever generator were analyzed in order to evaluate its potential for use in wireless sensor applications. The IDE embedded piezoelectric cantilever was designed and fabricated to have a self-resonance frequency of 126 Hz and acceleration of 1.57 G, respectively, for the mechanical resonance with a practical conveyor system in a thermal-power plant. It produced maximum output power of 2.81 mW under the resistive load of $160{\Omega}$ at 126 Hz. The wireless sensor module is electrically connected to a rectifier capacitor with capacity of 0.68 farad and 3.8 V for power supply by the piezoelectric cantilever generator. The unloaded capacitor could be charged as a rate of approximately $365{\mu}V/s$ while the capacitor exhibited that of 0.997 mV/min. during communication under low duty cycle of 0.2%. Therefore, it is considered that the fabricated IDE embedded piezoelectric cantilever generator can be used for wireless sensor applications.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.4
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• pp.301-308
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• 2016

In this study, a novel method referred as non-marker vision-based displacement measuring system(NVDMS) was introduced in order to measure the displacement of structure. There are two distinct differences between proposed NVDMS and existing vision-based displacement measuring system(VDMS). First, the NVDMS extracts the pixel coordinates of the structure using a feature point not a marker. Second, in the NVDMS, the scaling factor in order to convert the coordinates of a feature points from pixel value to physical value can be calculated by using the external conditions between the camera and the structure, which are distance, angle, and focal length, while the scaling factor for VDMS can be calculated by using the geometry of marker. The free vibration test using the three-stories scale model was conducted in order to analyze the reliability of the displacement data obtained from the NVDMS by comparing the reference data obtained from laser displacement sensor(LDS), and the measurement of dynamic characteristics was proceed using the displacement data. The NVDMS can accurately measure the dynamic displacement of the structure without the marker, and the high reliability of the dynamic characteristics obtained from the NVDMS are secured.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.1
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• pp.112-121
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• 2016

AFLS (Adaptive front lighting system) is being applied to improve safety in driving automotive at night. Safe embedded system design for controlling head-lamps is required to improve noise robust ECU hardware and software simultaneously by considering safety requirement of hardware-dependent software under severe environmental noise. In this paper, we propose an adaptive headlight controller with a newly-designed symmetric angle sensor compensator, especially based on the proposed steering-swivel angle lookup table to determine whether the current controlling target is safe. The proposed system includes an additional backup hardware to compare the system status and provides safe swivel-angle management using a controlling algorithm based on the pre-defined lookup table (LUT), which is a symmetric mapping relationship between the requested steering angle and expected swivel angle target. The implemented system model shows that the proposed architecture effectively detects abnormal situations and restores safe status of controlling the light-angle in AFLS operations under severe noisy environment.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.11
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• pp.1112-1120
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• 2009

In this paper, the authors introduced a new approach to find the target orbits of each satellite in order to establish a temporary reconnaissance constellation mission to minimize the average revisit time (ART) while satisfying the constraint on fuel limit. Two distinct problems are dealt with: the first is to reconnoiter the local area with discriminating fuel constraint the second is to reconnoiter ground moving target with same fuel constraint. A preliminary effort in applying a genetic algorithm to those problems has also been demonstrated through simulation study. The results show that current ARTs of each mission are reduced by 41% and 42%, respectively, by relocating the orbit of each satellite. Naturally, the final result may depend on satellite orbits, sensor characteristics, allowable fuel cost, thruster capability, and maneuver strategies.